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61.
Recently, five indole prenyltransferases from Aspergillus fumigatus have been proven biochemically to be responsible for prenylations of diverse substrates. In this study, we show peptidase activities of 7-DMATS, FgaPT1, CdpNPT, and FtmPT1, with preference for linear peptides containing a tryptophanyl moiety at the N terminus. Testing of 31 peptides revealed that these enzymes shared similar substrate specificity and accepted H-L-Trp-L-Ala-OH and H-L-Trp-Gly-OH as best substrates for aminopeptidase activity. By using H-L-Trp-Gly-OH as substrate, Km values at 350, 380, 300, and 420 microM and enzymatic rate constants kcat/Km at 0.51, 0.24, 0.53, and 0.14 mM(-1)s(-1) were determined for 7-DMATS, FgaPT1, CdpNPT, and FtmPT1, respectively. In contrast to prenyltransferase activities, the aminopeptidase activities were strongly or completely inhibited by EDTA. Mn2+ increased the aminopeptidase activities of FtmPT1 and CdpNPT up to 4- and 6-fold, respectively. To the best of our knowledge, this is the first report on the catalytic promiscuity of prenyltransferases. 相似文献
62.
Dr. Sven M. Elbert Anika Haidisch Tobias Kirschbaum Dr. Frank Rominger Dr. Ute Zschieschang Dr. Hagen Klauk Prof. Dr. Michael Mastalerz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(46):10585-10590
A new synthetic route to tetraindenopyrene (TIP)—a bowl-shaped cut-out structure of C70—is reported. The key step in this approach is a fourfold palladium-catalyzed C−H activation that increases the yield more than 50 times in comparison to the approach originally described by Scott and co-workers. Besides examination of its optoelectronic properties and study of its aggregation in solution, TIP was also re-investigated by dispersion-corrected DFT methods, which showed that dispersion interactions significantly increase the bowl-to-bowl inversion barrier. Furthermore, TIP was used as a semiconductor in p-channel thin-film transistors (TFTs). 相似文献
63.
Periodica Mathematica Hungarica - The aim of this paper is to continue the work started in Pavlovi? (Filomat 30(14):3725–3731, 2016) . We investigate further the properties of the local... 相似文献
64.
Dr. Martin R. Kotyrba Dr. Eduardo Cuervo‐Reyes Prof. Dr. Reinhard Nesper 《Angewandte Chemie (International ed. in English)》2015,54(33):9606-9609
YAlC was prepared by a flux method. It crystallizes as a partially filled‐up TlI structure, showing remarkable structural aspects at the border between Zintl phases and intermetallics. This novel ternary aluminide–carbide exhibits a unique one‐dimensional multi‐center bond and a polyacetylene‐related aluminum carbide substructure. The different functionalities of aluminum and of yttrium are quite remarkable. While the latter behaves more like a trivalent ion, aluminum contributes considerably to covalent bonding with carbon. Still yttrium d states contribute, but hardly in a directed manner. 相似文献
65.
Marc Goerigk Horst W. Hamacher Anika Kinscherff 《European Journal of Operational Research》2018,264(3):837-846
We present a new approach to handle uncertain combinatorial optimization problems that uses solution ranking procedures to determine the degree of robustness of a solution. Unlike classic concepts for robust optimization, our approach is not purely based on absolute quantitative performance, but also includes qualitative aspects that are of major importance for the decision maker.We discuss the two variants, solution ranking and objective ranking robustness, in more detail, presenting problem complexities and solution approaches. Using an uncertain shortest path problem as a computational example, the potential of our approach is demonstrated in the context of evacuation planning due to river flooding. 相似文献
66.
Back Cover: Preparation of Magnesium,Cobalt and Nickel Ferrite Nanoparticles from Metal Oxides using Deep Eutectic Solvents (Chem. Eur. J. 37/2016)
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67.
Philippe McGee Gabriel Bellavance Dr. Ilia Korobkov Anika Tarasewicz Prof. Louis Barriault 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9662-9665
During our efforts toward the synthesis of naturally occurring polyprenylated polycyclic acylphloroglucinol using a AuI‐catalyzed 6‐endo dig carbocyclization, we isolated stable vinyllic gold intermediates. Optimization lead to isolated yields of up to 98 %, using 2‐(di‐tert‐butylphosphino)biphenyl as the ligand. This transformation is derived from a silyl rearrangement that can be fully controlled according to the nature of the substituent on the ynone. This selective transformation does not require basic conditions to prevent protodeauration. These vinylgold complexes are the first isolated intermediates during a silyl migration with gold(I). More than 16 new organogold complexes were synthesized and characterized by single‐crystal X‐ray diffraction. Reactivity of these complexes is also presented. 相似文献
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Aisha Musaazi Sebunya Nakitto John H. Muyonga Yusuf Byenkya Byaruhanga Anika E. Wagner 《Molecules (Basel, Switzerland)》2021,26(7)
Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder of glucose homeostasis associated with a status of insulin resistance, impaired insulin signaling, β-cell dysfunction, impaired glucose and lipid metabolism, sub-clinical inflammation, and increased oxidative stress. Consuming fruits and vegetables rich in phytochemicals with potential antidiabetic effects may prevent T2DM and/or support a conservative T2DM treatment while being safer and more affordable for people from low-income countries. Solanum anguivi Lam. fruits (SALF) have been suggested to exhibit antidiabetic properties, potentially due to the presence of various phytochemicals, including saponins, phenolics, alkaloids, ascorbic acid, and flavonoids. For the saponin fraction, antidiabetic effects have already been reported. However, it remains unclear whether this is also true for the other phytochemicals present in SALF. This review article covers information on glucose homeostasis, T2DM pathogenesis, and also the potential antidiabetic effects of phytochemicals present in SALF, including their potential mechanisms of action. 相似文献
70.
Dr. Ralph Wieneke Anika Raulf Alina Kollmannsperger Prof. Mike Heilemann Prof. Robert Tampé 《Angewandte Chemie (International ed. in English)》2015,54(35):10216-10219
Protein labeling with synthetic fluorescent probes is a key technology in chemical biology and biomedical research. A sensitive and efficient modular labeling approach (SLAP) was developed on the basis of a synthetic small‐molecule recognition unit (Ni‐trisNTA) and the genetically encoded minimal protein His6‐10‐tag. High‐density protein tracing by SLAP was demonstrated. This technique allows super‐resolution fluorescence imaging and fulfills the necessary sampling criteria for single‐molecule localization‐based imaging techniques. It avoids masking by large probes, for example, antibodies, and supplies sensitive, precise, and robust size analysis of protein clusters (nanodomains). 相似文献